/*
    Copyright 2009 Robert Harder

    This file is part of the Brillig Toolkit.

    The Brillig Toolkit is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    The Brillig Toolkit is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with The Brillig Toolkit.  If not, see <http://www.gnu.org/licenses/>.
*/
package org.brillig.util;


/**
 * Encodes and decodes to and from Base64 notation.
 *
 * <p>
 * Change Log:
 * </p>
 * <ul>
 *  <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added
 *   some convenience methods for reading and writing to and from files.</li>
 *  <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems
 *   with other encodings (like EBCDIC).</li>
 *  <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the
 *   encoded data was a single byte.</li>
 *  <li>v2.0 - I got rid of methods that used booleans to set options. 
 *   Now everything is more consolidated and cleaner. The code now detects
 *   when data that's being decoded is gzip-compressed and will decompress it
 *   automatically. Generally things are cleaner. You'll probably have to
 *   change some method calls that you were making to support the new
 *   options format (<tt>int</tt>s that you "OR" together).</li>
 *  <li>v1.5.1 - Fixed bug when decompressing and decoding to a             
 *   byte[] using <tt>decode( String s, boolean gzipCompressed )</tt>.      
 *   Added the ability to "suspend" encoding in the Output Stream so        
 *   you can turn on and off the encoding if you need to embed base64       
 *   data in an otherwise "normal" stream (like an XML file).</li>  
 *  <li>v1.5 - Output stream pases on flush() command but doesn't do anything itself.
 *      This helps when using GZIP streams.
 *      Added the ability to GZip-compress objects before encoding them.</li>
 *  <li>v1.4 - Added helper methods to read/write files.</li>
 *  <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 *  <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream
 *      where last buffer being read, if not completely full, was not returned.</li>
 *  <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
 *  <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>
 * I am placing this code in the Public Domain. Do with it as you will.
 * This software comes with no guarantees or warranties but with
 * plenty of well-wishing instead!
 * Please visit <a href="http://iharder.net/base64">http://iharder.net/base64</a>
 * periodically to check for updates or to contribute improvements.
 * </p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 2.1
 */
public class Base64
{
    
/* ********  P U B L I C   F I E L D S  ******** */   
    
    
  /** No options specified. Value is zero. */
  public final static int NO_OPTIONS = 0;
    
  /** Specify encoding. */
  public final static int ENCODE = 1;
    
    
  /** Specify decoding. */
  public final static int DECODE = 0;
    
    
  /** Specify that data should be gzip-compressed. */
  public final static int GZIP = 2;
    
    
  /** Don't break lines when encoding (violates strict Base64 specification) */
  public final static int DONT_BREAK_LINES = 8;
    
    
/* ********  P R I V A T E   F I E L D S  ******** */  
    
    
  /** Maximum line length (76) of Base64 output. */
  private final static int MAX_LINE_LENGTH = 76;
    
    
  /** The equals sign (=) as a byte. */
  private final static byte EQUALS_SIGN = (byte)'=';
    
    
  /** The new line character (\n) as a byte. */
  private final static byte NEW_LINE = (byte)'\n';
    
    
  /** Preferred encoding. */
  private final static String PREFERRED_ENCODING = "UTF-8";
    
    
  /** The 64 valid Base64 values. */
  private final static byte[] ALPHABET;
  private final static byte[] _NATIVE_ALPHABET = /* May be something funny like EBCDIC */
  {
    (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
    (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
    (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U', 
    (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
    (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
    (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
    (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u', 
    (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
    (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', 
    (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/'
  };
    
  /** Determine which ALPHABET to use. */
  static
  {
    byte[] __bytes;
    try
    {
      __bytes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".getBytes( PREFERRED_ENCODING );
    }   // end try
    catch (java.io.UnsupportedEncodingException use)
    {
      __bytes = _NATIVE_ALPHABET; // Fall back to native encoding
    }   // end catch
    ALPHABET = __bytes;
  }   // end static
    
    
  /** 
   * Translates a Base64 value to either its 6-bit reconstruction value
   * or a negative number indicating some other meaning.
   **/
  private final static byte[] DECODABET =
  {   
    -9,-9,-9,-9,-9,-9,-9,-9,-9,                 // Decimal  0 -  8
    -5,-5,                                      // Whitespace: Tab and Linefeed
    -9,-9,                                      // Decimal 11 - 12
    -5,                                         // Whitespace: Carriage Return
    -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 14 - 26
    -9,-9,-9,-9,-9,                             // Decimal 27 - 31
    -5,                                         // Whitespace: Space
    -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,              // Decimal 33 - 42
    62,                                         // Plus sign at decimal 43
    -9,-9,-9,                                   // Decimal 44 - 46
    63,                                         // Slash at decimal 47
    52,53,54,55,56,57,58,59,60,61,              // Numbers zero through nine
    -9,-9,-9,                                   // Decimal 58 - 60
    -1,                                         // Equals sign at decimal 61
    -9,-9,-9,                                      // Decimal 62 - 64
    0,1,2,3,4,5,6,7,8,9,10,11,12,13,            // Letters 'A' through 'N'
    14,15,16,17,18,19,20,21,22,23,24,25,        // Letters 'O' through 'Z'
    -9,-9,-9,-9,-9,-9,                          // Decimal 91 - 96
    26,27,28,29,30,31,32,33,34,35,36,37,38,     // Letters 'a' through 'm'
    39,40,41,42,43,44,45,46,47,48,49,50,51,     // Letters 'n' through 'z'
    -9,-9,-9,-9                                 // Decimal 123 - 126
    /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
  };
    
  // I think I end up not using the BAD_ENCODING indicator.
  //private final static byte BAD_ENCODING    = -9; // Indicates error in encoding
  private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
  private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding

    
  /** Defeats instantiation. */
  private Base64(){}
    
    
    
/* ********  E N C O D I N G   M E T H O D S  ******** */    
    
    
  /**
   * Encodes up to the first three bytes of array <var>threeBytes</var>
   * and returns a four-byte array in Base64 notation.
   * The actual number of significant bytes in your array is
   * given by <var>numSigBytes</var>.
   * The array <var>threeBytes</var> needs only be as big as
   * <var>numSigBytes</var>.
   * Code can reuse a byte array by passing a four-byte array as <var>b4</var>.
   *
   * @param b4 A reusable byte array to reduce array instantiation
   * @param threeBytes the array to convert
   * @param numSigBytes the number of significant bytes in your array
   * @return four byte array in Base64 notation.
   * @since 1.5.1
   */
  private static byte[] encode3to4( byte[] b4, byte[] threeBytes, int numSigBytes )
  {
    encode3to4( threeBytes, 0, numSigBytes, b4, 0 );
    return b4;
  }   // end encode3to4

    
  /**
   * Encodes up to three bytes of the array <var>source</var>
   * and writes the resulting four Base64 bytes to <var>destination</var>.
   * The source and destination arrays can be manipulated
   * anywhere along their length by specifying 
   * <var>srcOffset</var> and <var>destOffset</var>.
   * This method does not check to make sure your arrays
   * are large enough to accomodate <var>srcOffset</var> + 3 for
   * the <var>source</var> array or <var>destOffset</var> + 4 for
   * the <var>destination</var> array.
   * The actual number of significant bytes in your array is
   * given by <var>numSigBytes</var>.
   *
   * @param source the array to convert
   * @param srcOffset the index where conversion begins
   * @param numSigBytes the number of significant bytes in your array
   * @param destination the array to hold the conversion
   * @param destOffset the index where output will be put
   * @return the <var>destination</var> array
   * @since 1.3
   */
  private static byte[] encode3to4( 
    byte[] source, int srcOffset, int numSigBytes,
    byte[] destination, int destOffset )
  {
    //           1         2         3  
    // 01234567890123456789012345678901 Bit position
    // --------000000001111111122222222 Array position from threeBytes
    // --------|    ||    ||    ||    | Six bit groups to index ALPHABET
    //          >>18  >>12  >> 6  >> 0  Right shift necessary
    //                0x3f  0x3f  0x3f  Additional AND
        
    // Create buffer with zero-padding if there are only one or two
    // significant bytes passed in the array.
    // We have to shift left 24 in order to flush out the 1's that appear
    // when Java treats a value as negative that is cast from a byte to an int.
    int inBuff =   ( numSigBytes > 0 ? ((source[ srcOffset     ] << 24) >>>  8) : 0 )
      | ( numSigBytes > 1 ? ((source[ srcOffset + 1 ] << 24) >>> 16) : 0 )
      | ( numSigBytes > 2 ? ((source[ srcOffset + 2 ] << 24) >>> 24) : 0 );

    switch( numSigBytes )
    {
    case 3:
      destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
      destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
      destination[ destOffset + 2 ] = ALPHABET[ (inBuff >>>  6) & 0x3f ];
      destination[ destOffset + 3 ] = ALPHABET[ (inBuff       ) & 0x3f ];
      return destination;
                
    case 2:
      destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
      destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
      destination[ destOffset + 2 ] = ALPHABET[ (inBuff >>>  6) & 0x3f ];
      destination[ destOffset + 3 ] = EQUALS_SIGN;
      return destination;
                
    case 1:
      destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
      destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
      destination[ destOffset + 2 ] = EQUALS_SIGN;
      destination[ destOffset + 3 ] = EQUALS_SIGN;
      return destination;
                
    default:
      return destination;
    }   // end switch
  }   // end encode3to4
    
    
    
  /**
   * Serializes an object and returns the Base64-encoded
   * version of that serialized object. If the object
   * cannot be serialized or there is another error,
   * the method will return <tt>null</tt>.
   * The object is not GZip-compressed before being encoded.
   *
   * @param serializableObject The object to encode
   * @return The Base64-encoded object
   * @since 1.4
   */
  public static String encodeObject( java.io.Serializable serializableObject )
  {
    return encodeObject( serializableObject, NO_OPTIONS );
  }   // end encodeObject
    


  /**
   * Serializes an object and returns the Base64-encoded
   * version of that serialized object. If the object
   * cannot be serialized or there is another error,
   * the method will return <tt>null</tt>.
   * <p>
   * Valid options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DONT_BREAK_LINES: don't break lines at 76 characters
   *     <i>Note: Technically, this makes your encoding non-compliant.</i>
   * </pre>
   * <p>
   * Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
   * <p>
   * Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
   *
   * @param serializableObject The object to encode
   * @param options Specified options
   * @return The Base64-encoded object
   * @see Base64#GZIP
   * @see Base64#DONT_BREAK_LINES
   * @since 2.0
   */
  public static String encodeObject( java.io.Serializable serializableObject, int options )
  {
    // Streams
    java.io.ByteArrayOutputStream  baos  = null; 
    java.io.OutputStream           b64os = null; 
    java.io.ObjectOutputStream     oos   = null; 
    java.util.zip.GZIPOutputStream gzos  = null;
        
    // Isolate options
    int gzip           = (options & GZIP);
    int dontBreakLines = (options & DONT_BREAK_LINES);
        
    try
    {
      // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
      baos  = new java.io.ByteArrayOutputStream();
      b64os = new Base64.OutputStream( baos, ENCODE | dontBreakLines );
    
      // GZip?
      if( gzip == GZIP )
      {
        gzos = new java.util.zip.GZIPOutputStream( b64os );
        oos  = new java.io.ObjectOutputStream( gzos );
      }   // end if: gzip
      else
        oos   = new java.io.ObjectOutputStream( b64os );
            
      oos.writeObject( serializableObject );
    }   // end try
    catch( java.io.IOException e )
    {
      e.printStackTrace();
      return null;
    }   // end catch
    finally
    {
      try{ oos.close();   } catch( Exception e ){}
      try{ gzos.close();  } catch( Exception e ){}
      try{ b64os.close(); } catch( Exception e ){}
      try{ baos.close();  } catch( Exception e ){}
    }   // end finally
        
        // Return value according to relevant encoding.
    try 
    {
      return new String( baos.toByteArray(), PREFERRED_ENCODING );
    }   // end try
    catch (java.io.UnsupportedEncodingException uue)
    {
      return new String( baos.toByteArray() );
    }   // end catch
        
  }   // end encode
    
    

  /**
   * Encodes a byte array into Base64 notation.
   * Does not GZip-compress data.
   *
   * @param source The data to convert
   * @since 1.4
   */
  public static String encodeBytes( byte[] source )
  {
    return encodeBytes( source, 0, source.length, NO_OPTIONS );
  }   // end encodeBytes
    


  /**
   * Encodes a byte array into Base64 notation.
   * <p>
   * Valid options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DONT_BREAK_LINES: don't break lines at 76 characters
   *     <i>Note: Technically, this makes your encoding non-compliant.</i>
   * </pre>
   * <p>
   * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
   * <p>
   * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
   *
   *
   * @param source The data to convert
   * @param options Specified options
   * @see Base64#GZIP
   * @see Base64#DONT_BREAK_LINES
   * @since 2.0
   */
  public static String encodeBytes( byte[] source, int options )
  {   
    return encodeBytes( source, 0, source.length, options );
  }   // end encodeBytes
    
    
  /**
   * Encodes a byte array into Base64 notation.
   * Does not GZip-compress data.
   *
   * @param source The data to convert
   * @param off Offset in array where conversion should begin
   * @param len Length of data to convert
   * @since 1.4
   */
  public static String encodeBytes( byte[] source, int off, int len )
  {
    return encodeBytes( source, off, len, NO_OPTIONS );
  }   // end encodeBytes
    
    

  /**
   * Encodes a byte array into Base64 notation.
   * <p>
   * Valid options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DONT_BREAK_LINES: don't break lines at 76 characters
   *     <i>Note: Technically, this makes your encoding non-compliant.</i>
   * </pre>
   * <p>
   * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
   * <p>
   * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
   *
   *
   * @param source The data to convert
   * @param off Offset in array where conversion should begin
   * @param len Length of data to convert
   * @param options Specified options
   * @see Base64#GZIP
   * @see Base64#DONT_BREAK_LINES
   * @since 2.0
   */
  public static String encodeBytes( byte[] source, int off, int len, int options )
  {
    // Isolate options
    int dontBreakLines = ( options & DONT_BREAK_LINES );
    int gzip           = ( options & GZIP   );
        
    // Compress?
    if( gzip == GZIP )
    {
      java.io.ByteArrayOutputStream  baos  = null;
      java.util.zip.GZIPOutputStream gzos  = null;
      Base64.OutputStream            b64os = null;
            
    
      try
      {
        // GZip -> Base64 -> ByteArray
        baos = new java.io.ByteArrayOutputStream();
        b64os = new Base64.OutputStream( baos, ENCODE | dontBreakLines );
        gzos  = new java.util.zip.GZIPOutputStream( b64os ); 
            
        gzos.write( source, off, len );
        gzos.close();
      }   // end try
      catch( java.io.IOException e )
      {
        e.printStackTrace();
        return null;
      }   // end catch
      finally
      {
        try{ gzos.close();  } catch( Exception e ){}
        try{ b64os.close(); } catch( Exception e ){}
        try{ baos.close();  } catch( Exception e ){}
      }   // end finally

      // Return value according to relevant encoding.
      try
      {
        return new String( baos.toByteArray(), PREFERRED_ENCODING );
      }   // end try
      catch (java.io.UnsupportedEncodingException uue)
      {
        return new String( baos.toByteArray() );
      }   // end catch
    }   // end if: compress
        
        // Else, don't compress. Better not to use streams at all then.
    else
    {
      // Convert option to boolean in way that code likes it.
      boolean breakLines = dontBreakLines == 0;
            
      int    len43   = len * 4 / 3;
      byte[] outBuff = new byte[   ( len43 )                      // Main 4:3
                                   + ( (len % 3) > 0 ? 4 : 0 )      // Account for padding
                                   + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines      
      int d = 0;
      int e = 0;
      int len2 = len - 2;
      int lineLength = 0;
      for( ; d < len2; d+=3, e+=4 )
      {
        encode3to4( source, d+off, 3, outBuff, e );

        lineLength += 4;
        if( breakLines && lineLength == MAX_LINE_LENGTH )
        {   
          outBuff[e+4] = NEW_LINE;
          e++;
          lineLength = 0;
        }   // end if: end of line
      }   // en dfor: each piece of array

      if( d < len )
      {
        encode3to4( source, d+off, len - d, outBuff, e );
        e += 4;
      }   // end if: some padding needed

            
      // Return value according to relevant encoding.
      try
      {
        return new String( outBuff, 0, e, PREFERRED_ENCODING );
      }   // end try
      catch (java.io.UnsupportedEncodingException uue)
      {
        return new String( outBuff, 0, e );
      }   // end catch
            
    }   // end else: don't compress
        
  }   // end encodeBytes
    

    
    
    
/* ********  D E C O D I N G   M E T H O D S  ******** */
    
    
  /**
   * Decodes four bytes from array <var>source</var>
   * and writes the resulting bytes (up to three of them)
   * to <var>destination</var>.
   * The source and destination arrays can be manipulated
   * anywhere along their length by specifying 
   * <var>srcOffset</var> and <var>destOffset</var>.
   * This method does not check to make sure your arrays
   * are large enough to accomodate <var>srcOffset</var> + 4 for
   * the <var>source</var> array or <var>destOffset</var> + 3 for
   * the <var>destination</var> array.
   * This method returns the actual number of bytes that 
   * were converted from the Base64 encoding.
   * 
   *
   * @param source the array to convert
   * @param srcOffset the index where conversion begins
   * @param destination the array to hold the conversion
   * @param destOffset the index where output will be put
   * @return the number of decoded bytes converted
   * @since 1.3
   */
  private static int decode4to3( byte[] source, int srcOffset, byte[] destination, int destOffset )
  {
    // Example: Dk==
    if( source[ srcOffset + 2] == EQUALS_SIGN )
    {
      // Two ways to do the same thing. Don't know which way I like best.
      //int outBuff =   ( ( DECODABET[ source[ srcOffset    ] ] << 24 ) >>>  6 )
      //              | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
      int outBuff =   ( ( DECODABET[ source[ srcOffset    ] ] & 0xFF ) << 18 )
        | ( ( DECODABET[ source[ srcOffset + 1] ] & 0xFF ) << 12 );
            
      destination[ destOffset ] = (byte)( outBuff >>> 16 );
      return 1;
    }
        
    // Example: DkL=
    else if( source[ srcOffset + 3 ] == EQUALS_SIGN )
    {
      // Two ways to do the same thing. Don't know which way I like best.
      //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
      //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
      //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
      int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] & 0xFF ) << 18 )
        | ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
        | ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) <<  6 );
            
      destination[ destOffset     ] = (byte)( outBuff >>> 16 );
      destination[ destOffset + 1 ] = (byte)( outBuff >>>  8 );
      return 2;
    }
        
    // Example: DkLE
    else
    {
      try{
        // Two ways to do the same thing. Don't know which way I like best.
        //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
        //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
        //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
        //              | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
        int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] & 0xFF ) << 18 )
          | ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
          | ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) <<  6)
          | ( ( DECODABET[ source[ srcOffset + 3 ] ] & 0xFF )      );

            
        destination[ destOffset     ] = (byte)( outBuff >> 16 );
        destination[ destOffset + 1 ] = (byte)( outBuff >>  8 );
        destination[ destOffset + 2 ] = (byte)( outBuff       );

        return 3;
      }catch( Exception e){
        System.out.println(""+source[srcOffset]+ ": " + ( DECODABET[ source[ srcOffset     ] ]  ) );
        System.out.println(""+source[srcOffset+1]+  ": " + ( DECODABET[ source[ srcOffset + 1 ] ]  ) );
        System.out.println(""+source[srcOffset+2]+  ": " + ( DECODABET[ source[ srcOffset + 2 ] ]  ) );
        System.out.println(""+source[srcOffset+3]+  ": " + ( DECODABET[ source[ srcOffset + 3 ] ]  ) );
        return -1;
      }   //e nd catch
    }
  }   // end decodeToBytes
    
    
    
    
  /**
   * Very low-level access to decoding ASCII characters in
   * the form of a byte array. Does not support automatically
   * gunzipping or any other "fancy" features.
   *
   * @param source The Base64 encoded data
   * @param off    The offset of where to begin decoding
   * @param len    The length of characters to decode
   * @return decoded data
   * @since 1.3
   */
  public static byte[] decode( byte[] source, int off, int len )
  {
    int    len34   = len * 3 / 4;
    byte[] outBuff = new byte[ len34 ]; // Upper limit on size of output
    int    outBuffPosn = 0;
        
    byte[] b4        = new byte[4];
    int    b4Posn    = 0;
    int    i         = 0;
    byte   sbiCrop   = 0;
    byte   sbiDecode = 0;
    for( i = off; i < off+len; i++ )
    {
      sbiCrop = (byte)(source[i] & 0x7f); // Only the low seven bits
      sbiDecode = DECODABET[ sbiCrop ];
            
      if( sbiDecode >= WHITE_SPACE_ENC ) // White space, Equals sign or better
      {
        if( sbiDecode >= EQUALS_SIGN_ENC )
        {
          b4[ b4Posn++ ] = sbiCrop;
          if( b4Posn > 3 )
          {
            outBuffPosn += decode4to3( b4, 0, outBuff, outBuffPosn );
            b4Posn = 0;
                        
            // If that was the equals sign, break out of 'for' loop
            if( sbiCrop == EQUALS_SIGN )
              break;
          }   // end if: quartet built
                    
        }   // end if: equals sign or better
                
      }   // end if: white space, equals sign or better
      else
      {
        System.err.println( "Bad Base64 input character at " + i + ": " + source[i] + "(decimal)" );
        return null;
      }   // end else: 
    }   // each input character
                                   
    byte[] out = new byte[ outBuffPosn ];
    System.arraycopy( outBuff, 0, out, 0, outBuffPosn ); 
    return out;
  }   // end decode
    
    
    
    
  /**
   * Decodes data from Base64 notation, automatically
   * detecting gzip-compressed data and decompressing it.
   *
   * @param s the string to decode
   * @return the decoded data
   * @since 1.4
   */
  public static byte[] decode( String s )
  {   
    byte[] bytes;
    try
    {
      bytes = s.getBytes( PREFERRED_ENCODING );
    }   // end try
    catch( java.io.UnsupportedEncodingException uee )
    {
      bytes = s.getBytes();
    }   // end catch
		//</change>
        
    // Decode
    bytes = decode( bytes, 0, bytes.length );
        
        
    // Check to see if it's gzip-compressed
    // GZIP Magic Two-Byte Number: 0x8b1f (35615)
    if( bytes != null && bytes.length >= 4 )
    {
            
      int head = (bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);       
      if( java.util.zip.GZIPInputStream.GZIP_MAGIC == head ) 
      {
        java.io.ByteArrayInputStream  bais = null;
        java.util.zip.GZIPInputStream gzis = null;
        java.io.ByteArrayOutputStream baos = null;
        byte[] buffer = new byte[2048];
        int    length = 0;

        try
        {
          baos = new java.io.ByteArrayOutputStream();
          bais = new java.io.ByteArrayInputStream( bytes );
          gzis = new java.util.zip.GZIPInputStream( bais );

          while( ( length = gzis.read( buffer ) ) >= 0 )
          {
            baos.write(buffer,0,length);
          }   // end while: reading input

          // No error? Get new bytes.
          bytes = baos.toByteArray();

        }   // end try
        catch( java.io.IOException e )
        {
          // Just return originally-decoded bytes
        }   // end catch
        finally
        {
          try{ baos.close(); } catch( Exception e ){}
          try{ gzis.close(); } catch( Exception e ){}
          try{ bais.close(); } catch( Exception e ){}
        }   // end finally

      }   // end if: gzipped
    }   // end if: bytes.length >= 2
        
    return bytes;
  }   // end decode


    

  /**
   * Attempts to decode Base64 data and deserialize a Java
   * Object within. Returns <tt>null</tt> if there was an error.
   *
   * @param encodedObject The Base64 data to decode
   * @return The decoded and deserialized object
   * @since 1.5
   */
  public static Object decodeToObject( String encodedObject )
  {
    // Decode and gunzip if necessary
    byte[] objBytes = decode( encodedObject );
        
    java.io.ByteArrayInputStream  bais = null;
    java.io.ObjectInputStream     ois  = null;
    Object obj = null;
        
    try
    {
      bais = new java.io.ByteArrayInputStream( objBytes );
      ois  = new java.io.ObjectInputStream( bais );
        
      obj = ois.readObject();
    }   // end try
    catch( java.io.IOException e )
    {
      e.printStackTrace();
      obj = null;
    }   // end catch
    catch( java.lang.ClassNotFoundException e )
    {
      e.printStackTrace();
      obj = null;
    }   // end catch
    finally
    {
      try{ bais.close(); } catch( Exception e ){}
      try{ ois.close();  } catch( Exception e ){}
    }   // end finally
        
    return obj;
  }   // end decodeObject
    
    
    
  /**
   * Convenience method for encoding data to a file.
   *
   * @param dataToEncode byte array of data to encode in base64 form
   * @param filename Filename for saving encoded data
   * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
   *
   * @since 2.1
   */
  public static boolean encodeToFile( byte[] dataToEncode, String filename )
  {
    boolean success = false;
    Base64.OutputStream bos = null;
    try
    {
      bos = new Base64.OutputStream( 
        new java.io.FileOutputStream( filename ), Base64.ENCODE );
      bos.write( dataToEncode );
      success = true;
    }   // end try
    catch( java.io.IOException e )
    {
            
      success = false;
    }   // end catch: IOException
    finally
    {
      try{ bos.close(); } catch( Exception e ){}
    }   // end finally
        
    return success;
  }   // end encodeToFile
    
    
  /**
   * Convenience method for decoding data to a file.
   *
   * @param dataToDecode Base64-encoded data as a string
   * @param filename Filename for saving decoded data
   * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
   *
   * @since 2.1
   */
  public static boolean decodeToFile( String dataToDecode, String filename )
  {
    boolean success = false;
    Base64.OutputStream bos = null;
    try
    {
      bos = new Base64.OutputStream( 
        new java.io.FileOutputStream( filename ), Base64.DECODE );
      bos.write( dataToDecode.getBytes( PREFERRED_ENCODING ) );
      success = true;
    }   // end try
    catch( java.io.IOException e )
    {
      success = false;
    }   // end catch: IOException
    finally
    {
      try{ bos.close(); } catch( Exception e ){}
    }   // end finally
        
    return success;
  }   // end decodeToFile
    
    
    
    
  /**
   * Convenience method for reading a base64-encoded
   * file and decoding it.
   *
   * @param filename Filename for reading encoded data
   * @return decoded byte array or null if unsuccessful
   *
   * @since 2.1
   */
  public static byte[] decodeFromFile( String filename )
  {
    byte[] decodedData = null;
    Base64.InputStream bis = null;
    try
    {
      // Set up some useful variables
      java.io.File file = new java.io.File( filename );
      byte[] buffer = null;
      int length   = 0;
      int numBytes = 0;
            
      // Check for size of file
      if( file.length() > Integer.MAX_VALUE )
      {
        System.err.println( "File is too big for this convenience method (" + file.length() + " bytes)." );
        return null;
      }   // end if: file too big for int index
      buffer = new byte[ (int)file.length() ];
            
      // Open a stream
      bis = new Base64.InputStream( 
        new java.io.BufferedInputStream( 
          new java.io.FileInputStream( file ) ), Base64.DECODE );
            
      // Read until done
      while( ( numBytes = bis.read( buffer, length, 4096 ) ) >= 0 )
        length += numBytes;
            
      // Save in a variable to return
      decodedData = new byte[ length ];
      System.arraycopy( buffer, 0, decodedData, 0, length );
            
    }   // end try
    catch( java.io.IOException e )
    {
      System.err.println( "Error decoding from file " + filename );
    }   // end catch: IOException
    finally
    {
      try{ bis.close(); } catch( Exception e) {}
    }   // end finally
        
    return decodedData;
  }   // end decodeFromFile
    
    
    
  /**
   * Convenience method for reading a binary file
   * and base64-encoding it.
   *
   * @param filename Filename for reading binary data
   * @return base64-encoded string or null if unsuccessful
   *
   * @since 2.1
   */
  public static String encodeFromFile( String filename )
  {
    String encodedData = null;
    Base64.InputStream bis = null;
    try
    {
      // Set up some useful variables
      java.io.File file = new java.io.File( filename );
      byte[] buffer = new byte[ (int)(file.length() * 1.4) ];
      int length   = 0;
      int numBytes = 0;
            
      // Open a stream
      bis = new Base64.InputStream( 
        new java.io.BufferedInputStream( 
          new java.io.FileInputStream( file ) ), Base64.ENCODE );
            
      // Read until done
      while( ( numBytes = bis.read( buffer, length, 4096 ) ) >= 0 )
        length += numBytes;
            
      // Save in a variable to return
      encodedData = new String( buffer, 0, length, Base64.PREFERRED_ENCODING );
                
    }   // end try
    catch( java.io.IOException e )
    {
      System.err.println( "Error encoding from file " + filename );
    }   // end catch: IOException
    finally
    {
      try{ bis.close(); } catch( Exception e) {}
    }   // end finally
        
    return encodedData;
  }   // end encodeFromFile
    
    
    
    
  /* ********  I N N E R   C L A S S   I N P U T S T R E A M  ******** */
    
    
    
  /**
   * A {@link Base64.InputStream} will read data from another
   * <tt>java.io.InputStream</tt>, given in the constructor,
   * and encode/decode to/from Base64 notation on the fly.
   *
   * @see Base64
   * @since 1.3
   */
  public static class InputStream extends java.io.FilterInputStream
  {
    private boolean encode;         // Encoding or decoding
    private int     position;       // Current position in the buffer
    private byte[]  buffer;         // Small buffer holding converted data
    private int     bufferLength;   // Length of buffer (3 or 4)
    private int     numSigBytes;    // Number of meaningful bytes in the buffer
    private int     lineLength;
    private boolean breakLines;     // Break lines at less than 80 characters
        
        
    /**
     * Constructs a {@link Base64.InputStream} in DECODE mode.
     *
     * @param in the <tt>java.io.InputStream</tt> from which to read data.
     * @since 1.3
     */
    public InputStream( java.io.InputStream in )
    {   
      this( in, DECODE );
    }   // end constructor
        
        
        /**
         * Constructs a {@link Base64.InputStream} in
         * either ENCODE or DECODE mode.
         * <p>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
         *
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @param options Specified options
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 2.0
         */
    public InputStream( java.io.InputStream in, int options )
    {   
      super( in );
      this.breakLines   = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
      this.encode       = (options & ENCODE) == ENCODE;
      this.bufferLength = encode ? 4 : 3;
      this.buffer   = new byte[ bufferLength ];
      this.position = -1;
      this.lineLength = 0;
    }   // end constructor
        
        /**
         * Reads enough of the input stream to convert
         * to/from Base64 and returns the next byte.
         *
         * @return next byte
         * @since 1.3
         */
    public int read() throws java.io.IOException 
    { 
      // Do we need to get data?
      if( position < 0 )
      {
        if( encode )
        {
          byte[] b3 = new byte[3];
          int numBinaryBytes = 0;
          for( int i = 0; i < 3; i++ )
          {
            try
            { 
              int b = in.read();
                            
              // If end of stream, b is -1.
              if( b >= 0 )
              {
                b3[i] = (byte)b;
                numBinaryBytes++;
              }   // end if: not end of stream
                            
            }   // end try: read
            catch( java.io.IOException e )
            {   
              // Only a problem if we got no data at all.
              if( i == 0 )
                throw e;
                            
            }   // end catch
          }   // end for: each needed input byte
                    
          if( numBinaryBytes > 0 )
          {
            encode3to4( b3, 0, numBinaryBytes, buffer, 0 );
            position = 0;
            numSigBytes = 4;
          }   // end if: got data
          else
          {
            return -1;
          }   // end else
        }   // end if: encoding
                
        // Else decoding
        else
        {
          byte[] b4 = new byte[4];
          int i = 0;
          for( i = 0; i < 4; i++ )
          {
            // Read four "meaningful" bytes:
            int b = 0;
            do{ b = in.read(); }
            while( b >= 0 && DECODABET[ b & 0x7f ] <= WHITE_SPACE_ENC );
                        
            if( b < 0 )
              break; // Reads a -1 if end of stream
                        
            b4[i] = (byte)b;
          }   // end for: each needed input byte
                    
          if( i == 4 )
          {
            numSigBytes = decode4to3( b4, 0, buffer, 0 );
            position = 0;
          }   // end if: got four characters
          else if( i == 0 ){
            return -1;
          }   // end else if: also padded correctly
          else
          {
            // Must have broken out from above.
            throw new java.io.IOException( "Improperly padded Base64 input." );
          }   // end 
                    
        }   // end else: decode
      }   // end else: get data
            
      // Got data?
      if( position >= 0 )
      {
        // End of relevant data?
        if( /*!encode &&*/ position >= numSigBytes )
          return -1;
                
        if( encode && breakLines && lineLength >= MAX_LINE_LENGTH )
        {
          lineLength = 0;
          return '\n';
        }   // end if
        else
        {
          lineLength++;   // This isn't important when decoding
          // but throwing an extra "if" seems
          // just as wasteful.
                    
          int b = buffer[ position++ ];

          if( position >= bufferLength )
            position = -1;

          return b & 0xFF; // This is how you "cast" a byte that's
          // intended to be unsigned.
        }   // end else
      }   // end if: position >= 0
            
      // Else error
      else
      {   
        // When JDK1.4 is more accepted, use an assertion here.
        throw new java.io.IOException( "Error in Base64 code reading stream." );
      }   // end else
    }   // end read
        
        
        /**
         * Calls {@link #read()} repeatedly until the end of stream
         * is reached or <var>len</var> bytes are read.
         * Returns number of bytes read into array or -1 if
         * end of stream is encountered.
         *
         * @param dest array to hold values
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @return bytes read into array or -1 if end of stream is encountered.
         * @since 1.3
         */
    public int read( byte[] dest, int off, int len ) throws java.io.IOException
    {
      int i;
      int b;
      for( i = 0; i < len; i++ )
      {
        b = read();
                
        //if( b < 0 && i == 0 )
        //    return -1;
                
        if( b >= 0 )
          dest[off + i] = (byte)b;
        else if( i == 0 )
          return -1;
        else
          break; // Out of 'for' loop
      }   // end for: each byte read
      return i;
    }   // end read
        
  }   // end inner class InputStream
    
    
    
    
    
    
  /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */
    
    
    
  /**
   * A {@link Base64.OutputStream} will write data to another
   * <tt>java.io.OutputStream</tt>, given in the constructor,
   * and encode/decode to/from Base64 notation on the fly.
   *
   * @see Base64
   * @since 1.3
   */
  public static class OutputStream extends java.io.FilterOutputStream
  {
    private boolean encode;
    private int     position;
    private byte[]  buffer;
    private int     bufferLength;
    private int     lineLength;
    private boolean breakLines;
    private byte[]  b4; // Scratch used in a few places
    private boolean suspendEncoding;
        
    /**
     * Constructs a {@link Base64.OutputStream} in ENCODE mode.
     *
     * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
     * @since 1.3
     */
    public OutputStream( java.io.OutputStream out )
    {   
      this( out, ENCODE );
    }   // end constructor
        
        
        /**
         * Constructs a {@link Base64.OutputStream} in
         * either ENCODE or DECODE mode.
         * <p>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
         * @param options Specified options.
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 1.3
         */
    public OutputStream( java.io.OutputStream out, int options )
    {   
      super( out );
      this.breakLines   = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
      this.encode       = (options & ENCODE) == ENCODE;
      this.bufferLength = encode ? 3 : 4;
      this.buffer       = new byte[ bufferLength ];
      this.position     = 0;
      this.lineLength   = 0;
      this.suspendEncoding = false;
      this.b4           = new byte[4];
    }   // end constructor
        
        
        /**
         * Writes the byte to the output stream after
         * converting to/from Base64 notation.
         * When encoding, bytes are buffered three
         * at a time before the output stream actually
         * gets a write() call.
         * When decoding, bytes are buffered four
         * at a time.
         *
         * @param theByte the byte to write
         * @since 1.3
         */
    public void write(int theByte) throws java.io.IOException
    {
      // Encoding suspended?
      if( suspendEncoding )
      {
        super.out.write( theByte );
        return;
      }   // end if: supsended
            
      // Encode?
      if( encode )
      {
        buffer[ position++ ] = (byte)theByte;
        if( position >= bufferLength )  // Enough to encode.
        {
          out.write( encode3to4( b4, buffer, bufferLength ) );

          lineLength += 4;
          if( breakLines && lineLength >= MAX_LINE_LENGTH )
          {
            out.write( NEW_LINE );
            lineLength = 0;
          }   // end if: end of line

          position = 0;
        }   // end if: enough to output
      }   // end if: encoding

      // Else, Decoding
      else
      {
        // Meaningful Base64 character?
        if( DECODABET[ theByte & 0x7f ] > WHITE_SPACE_ENC )
        {
          buffer[ position++ ] = (byte)theByte;
          if( position >= bufferLength )  // Enough to output.
          {
            int len = Base64.decode4to3( buffer, 0, b4, 0 );
            out.write( b4, 0, len );
            //out.write( Base64.decode4to3( buffer ) );
            position = 0;
          }   // end if: enough to output
        }   // end if: meaningful base64 character
        else if( DECODABET[ theByte & 0x7f ] != WHITE_SPACE_ENC )
        {
          throw new java.io.IOException( "Invalid character in Base64 data." );
        }   // end else: not white space either
      }   // end else: decoding
    }   // end write
        
        
        
        /**
         * Calls {@link #write(int)} repeatedly until <var>len</var> 
         * bytes are written.
         *
         * @param theBytes array from which to read bytes
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @since 1.3
         */
    public void write( byte[] theBytes, int off, int len ) throws java.io.IOException
    {
      // Encoding suspended?
      if( suspendEncoding )
      {
        super.out.write( theBytes, off, len );
        return;
      }   // end if: supsended
            
      for( int i = 0; i < len; i++ )
      {
        write( theBytes[ off + i ] );
      }   // end for: each byte written
            
    }   // end write
        
        
        
        /**
         * Method added by PHIL. [Thanks, PHIL. -Rob]
         * This pads the buffer without closing the stream.
         */
    public void flushBase64() throws java.io.IOException 
    {
      if( position > 0 )
      {
        if( encode )
        {
          out.write( encode3to4( b4, buffer, position ) );
          position = 0;
        }   // end if: encoding
        else
        {
          throw new java.io.IOException( "Base64 input not properly padded." );
        }   // end else: decoding
      }   // end if: buffer partially full

    }   // end flush

        
        /** 
         * Flushes and closes (I think, in the superclass) the stream. 
         *
         * @since 1.3
         */
    public void close() throws java.io.IOException
    {
      // 1. Ensure that pending characters are written
      flushBase64();

      // 2. Actually close the stream
      // Base class both flushes and closes.
      super.close();
            
      buffer = null;
      out    = null;
    }   // end close
        
        
        
        /**
         * Suspends encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
    public void suspendEncoding() throws java.io.IOException 
    {
      flushBase64();
      this.suspendEncoding = true;
    }   // end suspendEncoding
        
        
        /**
         * Resumes encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
    public void resumeEncoding()
    {
      this.suspendEncoding = false;
    }   // end resumeEncoding
        
        
        
  }   // end inner class OutputStream
    
    
}   // end class Base64
